Biology 223 Human Anatomy and Physiology Week 6

Biology 223 Human Anatomy and Physiology ! Week 6; Lecture 2; Wednesday Dr. Stuart S. Sumida Musculature and Innervation of Pectoral Limb

Cranial/dorsal Triceps = Quadriceps

Cranial/ventral Pectoral Group = Adductors

Caudal/dorsal Glutei = Deltoid Extensors = Extensors

Caudal/ventral Hamstrings = brachii Flexors = Flexors

Upper Limb Complications

1. Upper limb is not as firmly attached, so has extra muscles to hold it in place

2. There are several large, fan shaped muscles that do not exist in the lower limb

3 There is more migration of tissues during early development, making the 4 quadrants more complex

4. There is a large muscle that was not originally appendicular, so it has an unusual innervation and placement

Branchial (Gill Slit) Muscles Attaching Scapula to Body Wall

Trapezius In more primitive species used for opening and closing gills - a BRANCHIAL muscle. In humans, used to move scapula and keep head up

Trapezius Origin: Occipital bone, Spines of C 7 and T 1 -12 Insertion: Acromion Spine of scapula Lateral 1/3 of clavicle

Trapezius Innervation: Accessory Nerve (Cranial Nerve XI) Action: Extension of the head Elevation and depression of scapula

Trapezius

Axial Muscles Attaching Scapula to Body Wall

Serratus Anterior Origin: First 9 ribs Insertion: Medial edge of scapula’s deep surface

Serratus Anterior Innervation: Long thoracic nerve Action: Rotates scapula Primitively a BODY WALL MUSCLE

Serratus Anterior

Levator Scapulae Origin: Transverse processes of C 1 -4 Insertion: Medial edge of scapula

Levator Scapulae Innervation: Ventral Rami of C 3 and C 4 Action: Retracts scapula Depresses glenoid

Rhomdoidius Major Origin: Spines of T 2 -T 5 Insertion: Medial edge of scapula

Rhomdoidius Major Innervation: Dorsal Scapula Action: Retracts scapula Depresses glenoid

Rhomdoidius Minor Origin: Spines of C 7 and T 1 Insertion: Medial edge of scapula Note: minor is superior (cranial), but SMALLER

Rhomdoidius Minor Innervation: Dorsal Scapula Action: Retracts scapula Depresses glenoid

Levator Scapulae Rhomboid Minor Rhomboid Major

Rhomboids Pecoralis Minor Levator Scapulae Depression

Trapezius Serratus Anterior Elevation

Dorsal Appendicular Muscles

Latissimus Dorsi Origin: Spines of T 7 -T 12 Thoracolumbar fascia Insertion: Humerus: Inertubecular groove And lesser tubecular crest Innervation: Thoracodorsal Nerve

Latissiumus: Extends, adducts and medially rotates humerus Pectoralis: is large, fanshaped muscle opposing it ventrally

Ventral Musculature

The Pectoralis Group is a large, fan-shaped group that SPANS cranial-ventral and caudal-ventral regions.

Pectoralis Major: Clavicular Head: Origin: inferior margin of clavicle Insertion: Delto-pectoral crest of HUMERUS Sternal Head: Origin: Ventro-lateral margin of sternum Insertion: Delto-pectoral crest of HUMERUS

Pectoralis Major: Clavicular Head: Origin: inferior margin of clavicle Insertion: Greater tubercular crest of HUMERUS Innervation: Medial and lateral pectoral nerves

Pectoralis Major: Sternal Head: DEPRESSOR, ADDUCTOR of humerus Origin: Ventro-lateral margin of sternum; costal cartilages 1 -6 Insertion: Greater tubercular crest of HUMERUS Innervation: Medial and lateral pectoral nerves

Pectoralis MINOR: Deep to Pec. Major Origin: Ribs 3 -6. Insertion: Coracoid Process of Scapula Innervation: Function: Stabilization of scapula Positionally important for understanding location of other structures.

Musculature of the Shoulder: Muscles Connecting Scapula to Humerus

Elevators Teres Major Origin: Lower edge of scapula Insertion: Lesser tubercular crest Action: Extends, Adducts & Medially rotates humerus Innervation: Lower scapular

Elevators Subscapularis Origin: Deep surface of scapula Insertion: Lesser tubercle Action: Medially rotates humerus Innervation: Upper and lower scapular

Internal View: Subscapularis

Elevators Teres Minor Origin: Lower edge of scapula Insertion: Greater tubercle Action: Laterally rotates humerus Innervation: Axillary

Teres Minor

Elevators Deltoideus Origin: Lateral half of clavicle , Scapular spine, acromion process Insertion: Deltoid tuberosity of humerus Action: Abducts humerus (also flexes, extends, rotates and adducts) Innervation: Axillary nerve

Deltoid

Depressors Pectoralis Major (Sternal Head) Origin: Medial half of clavicle, sternum, costal cartilages 1 -6 Insertion: Greater tubercular crest Action: Medially rotates, flexes and adducts humerus Innervation: Lateral and medial pectoral

Depressors Supraspinatus Origin: Supraspinous fossa of scaupla Insertion: Greater tubercle of humerus Action: Abducts humerus Innervation: Subscapular

Depressors Infraspinatus Origin: Infraspinous fossa of scapula Insertion: Greater tubercle of humeus Action: Laterally rotates humerus Innervation: Subscapular

Supraspinatus Infraspinatus Teres Minor

Muscles of the Rotator Cuff Supraspinatus Infraspinatus Teres Minor Subscapularis

What You Should Know 1 SERIAL HOMOLOGIES Glutei Deltoid Adductors Pectoral group Quadriceps Triceps Hamstrings Brachii Extensors Flexors

What You Should Know 2: UPPER LIMB COMPLICATIONS • Explain 4. • Explain the movements of the scapula

What You Should Know 3: UPPER LIMB COMPLICATIONS • Origin, insertion, innervation and action of the following (Cartmill pages 224 -230) • Trapezius • Serratus anterior • Levator scapulae • Rhomboid major • Rhomboid minor • Latissimus Dorsi • Pectoralis Major (Sternal, Clavicular) and Minor

What You Should Know 4. THE SHOULDER Cartmill pages 231 -237 Origin, insertion, innervation and action of the following: Teres Major Subscapularis Teres minor Deltoid Pectoralis Major Supraspinatus Infraspinatus

Musculature Crossing the Elbow Joint

Muscles moving the elbow all cross the joint and insert on the bones of the forearm. They may originate from the scapula or the brachium (humerus).

D Which muscle is NOT a flexor of the elbow? C A B Answer =A Coracobrachialis

The Coracobrachialis makes up part of the mass of the upper arm but doesn’t actually cross the joint (scapula to humerus only).

Origin: coracoid process Insertion: Humerus Flexion and adduction of humerus. Musculocutaneous nerve

Elbow extensors Triceps brachii (Radial Nerve)

Cranial/dorsal Triceps = Quadriceps

Origin: Long Head: Glenoid Fossa Medial & Lateral Heads: Posterior surface of humeral shaft Insertion: Olecranon process of ulna Action: Extends elbow

Triceps Long Head Triceps, Lateral Head

Elbow flexors Brachii (brachial group) (Here, spelling counts…)

Caudal/ventral Hamstrings = brachii

Biceps brachii (musculocutaneous n. ) Origin: Short head: coracoid process Long head; glenoid fossa Insertion: Proximal radius Action: Flexes elbow supinates

Brachialis (musculocutaneous n. ) Origin: Humeral shaft Insertion Proximal ulna Action: flexes elbow

Corcobrachialis Biceps

Brachioradialis (Radial n. * exception) Origin: distal humerus Insertion: Styloid process of ulna Action: Flexes elbow

Brachioradialis Flexor Carpi Radialis Flexor Digitorum Superficialis Flexor Carpi Ulnaris

FLEXORS of the Wrist

Caudal/ventral Flexors = Flexors

Superficial Layer Flexor carpi radialis Median n. Origin: Medial epicondyle of humerus Insertion: Base of 2 nd & 3 rd metacarpals Action: Flexes wrist; abducts hand

Superficial Layer Palmaris longus Median n. Origin: Medial epicondyle of humerus Insertion: Palmar aponeurosis Action: Flexes wrist

Superficial Layer Flexor carpi ulnaris Ulnar n. Origin: Medial epicondyle of humerus Insertion: Pisiform and base of 5 th metacarpal Action: Flexes wrist; adducts hand

Intermediate Layer Flexor digitorum superficialis Median n Origin: Medial epicondyle of humerus Insertion: Middle phalanges of fingers 2 -5 Action: Flexes wrist and middle phalanges

Deep Layer Flexor pollicis longus Median n Origin: Anterior surface of radius Insertion: Distal phalanx of thumb Action: Flexes distal phalanx of thumb

Deep Layer Flexor digitorum profundus Median n Origin: Anteromedial surface ulna Insertion: Distal phalanges of fingers 2 -5 Action: Flexes distal phalanges

Brachioradialis Flexor Carpi Radialis Flexor Digitorum Superficialis Flexor Carpi Ulnaris

EXTENSORS of the Wrist

Caudal/dorsal Extensors = Extensors

Superficial Extensor carpi radialis brevis Radial n. Origin: Lateral epicondyle of humerus Insertion: Base of 3 rd metacarpal Action: Extends and abducts wrist

Superficial Extensor digitorum minimi Radial n. Origin: Lateral epicondyle of humerus Insertion: Distal phalange of little finger Action: Extends little finger

Superficial Extensor digitorum Radial n. Origin: Lateral epicondyle of humerus Insertion: Distal phalange of fingers 2 -4 Action: Extends fingers and wrist; abduct fingers

Extensor Carpi Ularis Extensor Indicis Extensor Digitorum Superficialis Extensor Carpi Radialis Abductor Pollicis Longus Extensor Retinaculum

Deep Extensor indices Radial n. Origin: Posterior surface of distal ulna Insertion: Extensor expansion of index finger Action: Extends index finger

Deep Extensor pollicis longus Radial n. Origin: Dorsal shaft of radius and ulna Insertion: Base of distal phalanx of thumb Action: Extends thumb

Deep Extensor pollicis brevis Radial n. Origin: Dorsal shaft of radius and ulna Insertion: Base of proximal phalanx of thumb Action: Extends thumb

Deep Abductor pollicis longus Radial n. Origin: Posterior surface of radius and ulna Insertion: Base of 1 st metacarpal Action: Abducts and extends thumb

Muscles of Pronation and Supination

Deep Abductor pollicis longus Radial n. Origin: Posterior surface of radius and ulna Insertion: Base of 1 st metacarpal Action: Abducts and extends thumb

Supination: Movement of the radius and ulna Lateral rotation of the arm so palm faces superiorally (anatomical position)

Ulna and Radius are parallel

Pronation: Opposite of supination Medial rotation of the arm so palm faces inferiorally Relaxed position

Ulna and Radius are crossed

Supination Supinator Radial n. Origin: Lateral epicondyle of humerus Insertion: Proximal end of radius Action: Supinates forearm

Supinator

Supination Biceps brachii musculocutaneous n. Origin: Short head: coracoid process Long head; glenoid fossa Insertion: Proximal radius Action: Flexes elbow supinates

Pronation Pronator teres Median n. Origin: Medial condyle of humerus Coronoid process of ulna Insertion: Lateral radius (midshaft) Action: Pronates forearm

Pronation Pronator quadratus Median n. Origin: Distal portion of anterior ulnar shaft Insertion: Distal surface of anterior radius Action: Pronates forearm

Pronator Teres Pronator Quadratus

What You Should Know 1: Muscles Crossing the Elbow Joint • Flexors (ventral) • Extensors (dorsal) 2: Muscles Crossing the Wrist Joint Flexors (ventral) Extensors (dorsal)

What You Should Know 3: Muscles of Elbow Extension, Flexion • Origin and Insertion • Innervation 3: Muscles of Pronation and Supination • Origin and Insertion • Innervation

What You Should Know 3: Serial Homologs of Major Groups 4: Functions of all Muscles Presented 5: A Summary of these muscles are in the Laboratory Manual and Cartmill’s Text.